IgG Enzyme-linked Immunosorbent Assay Research Articles

Evaluation of the Epitogen Lyme Detect IgG ELISA: a novel peptide multiplexing approach.

Lyme Borreliosis (LB), or Lyme disease, is a growing health concern caused by Borrelia burgdorferi sensu lato (Bbsl) bacteria transmitted through tick bites, and untreated cases can lead to severe health complications. Existing serology tests, while valuable, have low sensitivity in early infection stages where diagnosis is vital, interpretation variability, and false positives from cross-reactivity, while direct detection methods also suffer from low sensitivity, due to the inconsistent presence of Bbsl components in clinical samples. This study validated the diagnostic performance of the novel Epitogen Lyme Detect IgG enzyme-linked immunosorbent assay (ELISA) based on scaffold-displayed peptide antigens, using 120 specific immunodominant epitopes selected from 37 antigenic bacterial proteins corresponding to the main pathogenic Bbsl genospecies. Using 220 serum samples from Scottish patients with early, late, and disseminated LB, the assay's sensitivity was compared with that of the LIAISON Borrelia IgG CLIA, while specificity was assessed with 198 control samples, including healthy individuals and patients with diseases that are humorally similar. The Epitogen Lyme Detect IgG assay demonstrated comparable performance to the LIAISON Borrelia IgG in disseminated and late LB (Lyme neuroborreliosis, acrodermatitis chronica atrophicans, and Lyme arthritis). Notably, the Epitogen Lyme Detect IgG showed significantly higher sensitivity in patients with suspected erythema migrans, while maintaining high specificity. The Epitogen Lyme Detect IgG ELISA offers a promising advancement in LB diagnostics, demonstrating its potential for more accurate and timely diagnosis, particularly in the early stages of LB infection.IMPORTANCELyme Borreliosis (LB), caused by Borrelia burgdorferi sensu lato bacteria, poses significant health risks if undiagnosed or diagnosed late. Current diagnostic tests have limitations, especially in early-stage detection. This study validates the Epitogen Lyme Detect IgG enzyme-linked immunosorbent assay, demonstrating superior sensitivity in early LB detection while maintaining high specificity. The Epitogen Lyme Detect IgG comprises a suite of 120 immunodominant IgG epitopes/peptides from 37 bacterial antigens, covering the main LB-causing species: Borrelia burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, and Borrelia mayonii. The novel design of multiplexing peptide antigens onto a scaffold to facilitate expression, correct folding, and orientation of the relevant peptides offers a promising advancement, potentially leading to more accurate and timely LB diagnoses and improving patient outcomes.

Detection of human strongyloidiasis among patients with a high risk of complications attending selected tertiary care hospitals in Colombo, Sri Lanka using molecular and serological diagnostic tools

BackgroundStrongyloidiasis a neglected tropical disease is known to cause severe disease among immunosuppressed and has not been studied extensively in Sri Lanka. Parasitological diagnostic approaches based on faecal microscopy and culture often fail to detect low-intensity infections. This study investigates the presence of strongyloidiasis among selected immunocompromised individuals using parasitological, molecular and serological techniques.MethodsAdult patients with immunocompromising conditions admitted to three tertiary care hospitals in Sri Lanka were recruited. A faecal sample and 2 ml of venous blood were collected. The faecal samples were subjected to direct faecal smear and cultures (agar plate, charcoal and Harada-Mori) and polymerase chain reaction (PCR) using species specific primers designed for Strongyloides stercoralis. The presence of Strongyloides IgG antibodies was tested in the collected serum samples using DRG Strongyloides IgG enzyme-linked immunosorbent assay (ELISA) kits. The PCR products of the positive samples were sequenced using Sanger sequencing method.ResultsA total of 260 patients were recruited to this study, out of which 160 provided faecal samples and 122 provided blood samples. Out of the 160 faecal samples, none were positive for strongyloidiasis by direct smear, charcoal and Harada-Mori cultures. Only one sample (0.6%) was positive by agar plate culture. Out of the 123 samples subjected to PCR, 14 (11.4%), including the culture positive patient, were positive for S. stercoralis. Sequencing results of the PCR products indicated 100% similarity to S. stercoralis. Out of the 122 serum samples subjected to ELISA, 20 (16.4%), including the culture positive patient, were positive for Strongyloides IgG antibodies. However, sociodemographic, exposure factors, clinical features were not significantly associated with the presence of strongyloidiasis infection.ConclusionsStrongyloidiasis is present among the immunocompromised population in Sri Lanka, even in the absence of a significant relationship with associated factors. It is advisable to screen such patients with highly sensitive tests such as PCR for early diagnosis and treatment.Graphical

Comparison of the indirect immunofluorescence assay and a commercial ELISA to detect KSHV antibodies.

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus involved in several diseases. The gold standard for KSHV sero diagnosis remains the indirect immunofluorescence assay (IFA), which is time-consuming and operator-dependent. We compared this method with an enzyme-linked immunosorbent assay (ELISA) targeting solubilized KSHV whole-genome extract among positive (n = 49, including 76% of HIV-infected patients) and negative (n = 14) control groups. We also included 14 sera with equivocal IFA results. ELISA showed better performance in detecting KSHV antibodies (McNemar's test, P = 0.0455). The sensitivity and specificity of both methods were 79% (64-89) and 100% (66-100) for the IFA, respectively, and 94% (83-99) and 100% (66-100) for ELISA, respectively. All IFA equivocal results were either negative or positive with ELISA. ELISA is more reliable and could be a good alternative for determining KSHV serological status, particularly in the context of immunocompromised patients and equivocal serology with the IFA.IMPORTANCEKaposi's sarcoma-associated herpesvirus (KSHV) sero status remains challenging because no perfect reference is available for the detection of KSHV antibodies. The current gold-standard method, the indirect immunofluorescence assay (IFA), has a very good specificity of close to 100%, but a lower sensitivity of around 80-85%, which decreases to 64-67% in immunocompromised patients. Additionally, this method is time-consuming and operator-dependent compared with new serological assays such as the enzyme-linked immunosorbent assay (ELISA). Thus, further research is still needed to improve KSHV sero diagnosis. Here, we compare the KSHV IgG ELISA kit assay (Advanced Biotechnologies Inc) with the gold-standard IFA, targeting the LANA-1 protein from latent BC-3 cell lines.

Exposure patterns and the risk factors of Crimean Congo hemorrhagic fever virus amongst humans, livestock and selected wild animals at the human/livestock/wildlife interface in Isiolo County, upper eastern Kenya.

Crimean Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease caused by CCHF virus (CCHFV). The disease has a complex transmission cycle that involves a wide range of hosts including mammalian and some species of birds. We implemented a sero-epidemiological study in Isiolo County, Kenya, to determine relative seroprevalences of CCHFV in humans, livestock and in wild animals. In addition, we identified subject and environment level factors that could promote exposure to CCHFV. Humans (n = 580) and livestock (n = 2,137) were recruited into the study through a multistage random sampling technique, and in addition, various species of wild animals (n = 87) were also sampled conveniently. Serum samples from all recruited humans and animals were collected and screened for CCHFV antibodies using ID Screen multispecies, double-antigen IgG enzyme-linked immunosorbent assay (ELISA). The overall anti-CCHFV IgG seroprevalences in humans, cattle, goats, sheep and camels were 7.2% [95% CI: 3.1-15.8%], 53.9% [95% CI: 30.7-50.9%], 11.6% [95% CI: 7.2-22.5%], 8.6% [95% CI: 3-14%] and 89.7% [95% CI: 78-94%], respectively. On average, the sampled wild animals had CCHFV seroprevalence of 41.0% [95% CI: 29.1-49.4%]; giraffes had the highest mean CCHF seroprevalence followed by buffaloes, while impala had very low exposure levels. Statistical analyses using mixed effects logistic regression models showed that CCHFV exposure in humans was significantly associated with male gender, being over 30 years of age and belonging to a household with a seropositive herd. In livestock, a combination of animal- and environment level factors including older animals, being in an area with high normalized difference vegetation index (NDVI) and high vapour pressure deficit were significantly associated with CCHFV infection. Age, sex and species of wild animals were considered as the key risk factors in the analysis, but none of these variables was significant (P-value = 0.891, 0.401 and 0.664, respectively). Additionally, RT-qPCR analysis revealed the presence of CCHFV RNA in camels (30%), cattle (14.3%), and goats (3.8%), but not in humans, sheep, or wild animals. This study demonstrates that environmental factors, such as NDVI and vapor pressure deficit, affect CCHFV exposure in livestock, while the presence of infected livestock is the key determinant of human exposure at the household level. These findings underscore the importance of using One Health approaches to control the disease in human-livestock-wildlife interfaces. For instance, the existing CCHF surveillance measures could be enhanced by incorporating algorithms that simulate disease risk based on the environmental factors identified in the study. Additionally, tick control in livestock, such as the use of acaricides, could reduce CCHFV exposure in livestock and, consequently, in humans.

Association between infection with Helicobacter pylori and metabolic syndrome among diabetic patients attending Jimma medical center in Jimma city, Ethiopia: a cross-sectional study

BackgroundPrevious studies have implicated the role of H. pylori infection in developing the metabolic syndrome. However, findings remain contradictory, and data from developing countries are scarce.MethodsWe employed a cross-sectional study design to assess the relationship between H. pylori infection and metabolic syndrome among diabetic patients attending Jimma Hospital, Ethiopia. An interviewer-led questionnaire administered to study participants provided information on sociodemographic factors, and medical records were used to obtain medical history information. Metabolic parameters, including plasma glucose, triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), body-mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were collected. H. pylori infection status was assessed using IgG Enzyme-linked Immunosorbent Assays (ELISA). The effect of H. pylori infection on metabolic syndrome and metabolic parameters was determined using multivariate linear and logistic regressions.ResultsWe found H. pylori infection status was positively but not significantly associated with metabolic syndrome (AOR = 1.507, 95% CI: 0.570–3.981, p = 0.408). When the analysis was restricted to individual metabolic parameters, H. pylori positivity was significantly associated with lower HDL-c and higher SB, respectively.ConclusionsOur result confirms that individual metabolic parameters, not an overall metabolic syndrome, are significantly associated with H. pylori infection. Future studies should examine the relationship between H. pylori and metabolic syndrome, considering gastrointestinal conditions such as GERD, GU, and DU.

Thrombotic antiphospholipid syndrome: Recurrent thromboses

Thrombotic antiphospholipid syndrome (APS) is a condition affecting young people in whom a thromboembolic event occurs in the presence of circulating antiphospholipid antibodies (aPL).The aim of this study was the evaluation of the incidence of recurrent thrombosis and its risk factors in antiphospholipid syndrome.Material and methods. The retrospective study included 98 patients with aPL who were followed up at the institute from 2014 to 2023, of whom 66 (67%) were women and 32 (33%) were men. Of the 98 patients with aPL, 48 (49%) had a diagnosis of systemic lupus erythematosus (SLE). Antiphospholipid antibodies (aPL), including antibodies to cardiolipin (IgG/IgM aCL), antibodies to ß2-glycoprotein 1 (IgG/IgM aß2GP1), antibodies to ß2-glycoprotein IgG against domain 1 (IgG aß2GP1-D1), antibodies to phosphatidylserine/prothrombin complex (IgG/ IgM aPS/PT) and other thrombotic risk factors. aPL was assessed by enzyme-linked immunosorbent assay (ELISA) and chemoluminescence assay (CHLA).Results. Thrombosis recurrence was reported in 62 (63%) of 98 patients, and 36 (35%) did not. The main cause of recurrent thrombosis was treatment with direct oral anticoagulants (DOACs). 24 (38.7%) of 62 patients with recurrent thrombosis were treated with DOACs, the duration of which ranged from 6 to 24 months. The next most common cause of recurrent thrombosis was the lack of continuous anticoagulant therapy in 20 (32.5%) of the patients. In 17 (27.4%) of the patients, the recurrence occurred while they were still taking warfarin. In 10 (41.7%) of the 24 patients, the recurrent thrombosis was arterial in origin. This was associated with recurrent cerebral circulation problems. The level of positivity did not matter, but all had triple IgG aPL positivity. 5 had lupus anticoagulant (LA) at the onset of the disease before anticoagulant use. IgG aPS/PT was most important in association with recurring thrombosis in the ELISA: 45 (72.6%) of 62 patients with recurring thrombosis were positive for IgG aPS/PT, compared with 19 (52.8%) of 36 patients without recurring thrombosis. The detection of all aPL was more frequent in CHMA than in ELISA. However, the definition of aPL in ELISA is recommended according to the latest classification criteria. Triple IgG positivity for aCL of IgG aß2GP1, IgG aß2GP1-D1 and CHMA remained a risk factor for recurrent thrombosis and increased the risk of recurrence more than threefold. Obesity was a risk factor for recurrent thrombosis, with a 5-fold increased risk of recurrent thrombosis in obese compared to non-obese patients (p=0.01).Conclusions. Recurrent thrombosis in APS is largely associated with IgG aCL, IgG aß2GP1, IgG aß2GP1-D1, IgG aPS/PT. Triple IgG aPL positivity in any combination significantly increased recurrent thrombosis risk.The presence of any type of aPL IgG in both ELISA and CHLA influenced the recurrence rate of thrombosis in APS.Obesity was a significant risk factor for recurrent thrombosis.

Monoclonal Antibodies for Rift Valley Fever Virus Nucleocapsid: Application in IgG/IgM ELISA for Sero-Diagnosis.

Rift Valley fever virus (RVFV) belonging to the Phenuiviridae family is responsible for a zoonotic disease called Rift Valley fever (RVF). Currently, RVFV has spread from Africa to Asia, and due to its ability to cause high mortality rates, it has significantly impacted human health and economic development in many societies. Highly specific and sensitive systems for sero-diagnosis of RVFV infection are needed for clinical use. BALB/c mice were immunized with recombinant RVFV nucleocapsid (rRVFV-N) protein and the spleen cells fused with SP2/0 myeloma cells to create hybridoma cell lines. The secreted monoclonal antibodies (MAbs) were purified and characterized. Enzyme-linked immunosorbent assay (ELISA) systems for the detection of IgG and IgM using the new MAbs were established and evaluated. Serum samples from 96 volunteers and 93 patients of suspected RVF from Kenya were tested compared with the ELISA systems based on inactivated viruses and the rabbit polyclonal antibody. Three monoclonal antibodies against rRVFV-N protein were established. The performance of the MAb-based sandwich IgG ELISA and the IgM capture ELISA perfectly matched the ELISA systems using the inactivated virus or the polyclonal antibody. Recombinant RVFV-N protein-specific MAbs were developed and they offer useful tools for RVFV studies. The MAb-based ELISA systems for detecting IgG and IgM offer safe and useful options for diagnosing RVFV infections in humans.

Proton Nuclear Magnetic Resonance (1H NMR) Metabolomics Study in Serum, Urine, and Cystic Fluid for Differentiating Fertility and Staging of Intra-abdominal Hydatid Cyst in Adults.

Cystic echinococcosis (CE) is a parasitic zoonosis caused by the tapeworm Echinococcus granulosus. Over the past few years, a lot of research has been done on liver illnesses using metabolomics techniques to identify biomarkers which could identify the diseases in its early stages. The present study was done to explore biomarkers in serum, urine, and cystic fluid which would help in differentiating, staging, and assessing fertility of intra-abdominal hydatid cyst by using proton nuclear magnetic resonance (1H NMR) metabolomics. In the study, 28 subjects (16 cases and 12 controls) were enrolled. Staging of hydatid cysts was performed using ultrasonography. In patients complying with case and control definition, blood, urine, and cystic fluid were collected for complete blood count, urine culture, Echinococcus IgG enzyme-linked immunosorbent assay (ELISA), and metabolomic analysis. The 17, 15, and 11 metabolites in serum, urine, and cystic fluid samples were quantified, respectively, to differentiate between case and control group. In this study, we observed that there was a significant downregulation of succinate metabolite in urine samples of cases, down-regulation of five metabolites (isoleucine, valine, histidine, tyrosine and formate) and upregulation of alanine in cystic fluid of cases. Current study demonstrates that metabolomics can be used non-invasively for rapid diagnosis of CE. This is one of the very few studies, which used 1H NMR spectroscopy, to analyze the profile of metabolites in serum, urine, and cystic fluid in cases of CE and controls. Raj N, Pandey A, Roy R, et al. Proton Nuclear Magnetic Resonance (1H NMR) Metabolomics Study in Serum, Urine, and Cystic Fluid for Differentiating Fertility and Staging of Intra-abdominal Hydatid Cyst in Adults. Euroasian J Hepato-Gastroenterol 2024;14(1):30-34.

An indirect ELISA for detecting anti-SARS-CoV-2 antibodies in human sera using a baculovirus-expressed recombinant nucleocapsid antigen

This study focuses on the development and initial assessment of an indirect IgG enzyme-linked immunosorbent assay (ELISA) specifically designed to detect of anti-SARS-CoV-2 antibodies. The unique aspect of this ELISA method lies in its utilization of a recombinant nucleocapsid (N) antigen, produced through baculovirus expression in insect cells. Our analysis involved 292 RT-qPCR confirmed positive serum samples and 54 pre-pandemic healthy controls. The process encompassed cloning, expression, and purification of the SARS-CoV-2 N gene in insect cells, with the resulted purified protein employed in our ELISA tests. Statistical analysis yielded an Area Under the Curve of 0.979, and the optimized cut-off exhibited 92 % sensitivity and 94 % specificity. These results highlight the ELISA's potential for robust and reliable serological detection of SARS-CoV-2 antibodies. Further assessments, including a larger panel size, reproducibility tests, and application in diverse populations, could enhance its utility as a valuable biotechnological solution for diseases surveillance.

Seroprevalence of the novel swine acute diarrhea syndrome coronavirus in China assessed by enzyme-linked immunosorbent assay.

The endemic outbreak of SADS-CoV has resulted in economic losses and potentially threatened the safety of China's pig industry. The molecular epidemiology of SADS-CoV in pig herds has been investigated in many provinces in China. However, there are no data over a long-time span, and there is a lack of extensive serological surveys to assess the prevalence of SADS-CoV in Chinese swine herds since the discovery of SADS-CoV. In this study, an indirect anti-SADS-CoV IgG enzyme-linked immunosorbent assay (ELISA) based on the SADS-CoV S1 protein was established to investigate the seroprevalence of SADS-CoV in Chinese swine herds. Cross-reactivity assays, indirect immunofluorescence, and western blotting assays showed that the developed ELISA had excellent SADS-CoV specificity. In total, 12,978 pig serum samples from 29 provinces/municipalities/autonomous regions in China were tested from 2022 to 2023. The results showed that the general seroprevalence of SADS-CoV in China was 59.97%, with seroprevalence ranging from 16.7% to 77.12% in different provinces and from 42.61% to 68.45% in different months. SADS-CoV is widely prevalent in China, and its seroprevalence was higher in Northeast China, North China, and Central China than in other regions. Among the four seasons, the prevalence of SADS-CoV was the highest in spring and the lowest in autumn. The results of this study provide the general seroprevalence profile of SADS-CoV in China, facilitating the understanding of the prevalence of SADS-CoV in pigs. More importantly, this study is beneficial in formulating preventive and control measures for SADS-CoV and may provide directions for vaccine development.

Comparison of an Enzyme Linked-Immunosorbent Assay and a Chemiluminescent Immunoassay with an Immunofluorescence Assay for Detection of Phase II IgM and IgG Antibodies to Coxiella burnetii.

In this study, we have compared the detection of IgM and IgG against C. burnetii phase II of an enzyme-linked immunosorbent assay (ELISA) (Euroimmun) and a chemiluminescent immunoassay (CLIA) (VIRCLIA, Vircell). In addition, an indirect immunofluorescence assay (IFA) was used as a reference test. One hundred forty-eight sera were used for IgG evaluation, and eighty-eight for IgM. The sensitivity of ELISA and CLIA in detecting phase II IgM was excellent. On the other hand, the CLIA IgM showed better specificity than the ELISA IgM. As for phase II IgG, the specificity of ELISA and CLIA was similar, while the ELISA technique showed a higher sensitivity. In conclusion, the best system to detect phase II IgM antibodies against C. burnetii is the CLIA from Vircell, which is characterized by high sensitivity and specificity. For the detection of phase II IgG, the Euroimmun ELISA and Vircell CLIA assays are suitable for the determination of this marker in the laboratory, although the IgG ELISA has greater sensitivity.

Seroepidemiology of Toxoplasma gondii in diabetic patients type 2 by enzyme-linked immunosorbent assay method in Zabol City, 2017-2018.

Type 2 diabetes mellitus (T2DM) is prone to opportunistic infections, including toxoplasmosis, due to an immunodeficiency system. This study aimed to evaluate the serum of people with T2DM to determine the titer of anti-toxoplasma antibodies in patients and compare it with the control group. 720 blood samples have been carried out between October and the end of January 2017 in Sistan, and Baluchestan provinces in southeastern Iran, of these, 360 samples were related to healthy individuals (control), and 360 samples were related to T2DM individuals. The immunoglobulin (Ig) M and IgG enzyme-linked immunosorbent assay methods have been used to detect toxoplasmosis. The data were analyzed using SPSS-19, Chi-square, and Fisher's exact test to compare statistical parameters. In this cross-sectional study, out of 360 samples of T2DM by ELISA method, 60% samples in diabetic patients and 48.1% in control group were IgG positive (P < 0.05). Nearly 2.5% samples in diabetic patients and 0.3% in control group were IgM positive (P < 0.05). Anti-toxoplasma antibodies including IgG and IgM were higher in diabetic patient in comparison to control group.

Evaluation of Three Cytomegalovirus IgG Lateral Flow Assays for Rapid Determination of CMV Serostatus.

Cytomegalovirus (CMV) serostatus is a major determinant of CMV infection, disease risk, and transplant outcomes. Current clinical serology assays are limited by relatively slow turnaround time, design for batched testing, need for trained personnel, and/or specialized equipment. Rapid diagnostic assays in development have a role in emerging settings, such as critically ill patients, but have not been systematically evaluated. We assessed the performance of 3 rapid lateral flow assays (LFAs) for the detection of CMV immunoglobulin (Ig)G antibodies compared with a reference commercially available CMV IgG enzyme-linked immunosorbent assay in residual serum samples from 200 consecutive adults who underwent clinical CMV serology testing. Samples with discrepant results between the LFA and reference assay were tested by a second reference assay. A subset of serum samples was assessed for interoperator variability. Operating characteristics of the QooLabs LFA were separately assessed in plasma samples. The sensitivity and specificity of the individual LFA assays using serum varied significantly: 86%/83%, 99/93%, and 57/97%, for Healgen, QNow automated reader, and nanoComposix, respectively, compared with the reference assay. Results for the QNow assay were comparable between automated and manual reads. Among a subset of 10 serum samples assessed by 5 individual operators, 44 of 50 (88%) results were concordant. Among 50 plasma samples assessed by the QooLabs LFA, the sensitivity and specificity were 72% and 96%. The ease of performance, rapid turnaround time, and good operating characteristics provide the rationale for further evaluation of the Qoolabs QNow LFA in specialized settings where rapid assessment of CMV serostatus would be advantageous.

Seroprevalence of Infection by Borrelia Species Responsible for Lyme Disease in the French Alps: Analysis of 27,360 Serology Tests, 2015-2020.

Objectives: Lyme borreliosis incidence is increasing in several areas; moreover, it has recently gained the public's attention. Apart from erythema migrans, Lyme disease diagnosis relies (among others) on serology test; however, the prevalence of positive enzyme-linked immunosorbent assay (ELISA) and western blot (WB) assay has been poorly studied in the general population. We aimed to approach the seroprevalence of infection by Borrelia species responsible for Lyme disease in the French Isere department using city laboratories data. Patients and Methods: We retrieved all serological tests for Borrelia species responsible for Lyme disease performed in the two main networks of city laboratories between 2015 and 2020. All patients with both ELISA and WB IgG were considered seropositive. Results: We analyzed 27,360 tests (ELISA/ELISA+WB). Mean age was 50.9 ± 20.3 years (ranges: 0-101), with 57.1% females. Overall, 11.7% had IgG detected by ELISA, and 4.7% had IgG detected by both ELISA and WB assay. Seropositive status was more frequent in males (7.0% vs. 2.9%, p < 0.001). Seropositivity rate increased with age after a first peak in childhood; men aged 61-70 years had the highest seropositivity rate (10.3%). In addition, seropositivity rate was higher in persons from a rural area. In multivariate analysis, older age, male gender and living in a rural area were independently associated with seropositivity. Seropositivity rate was stable on the 2017-2020 period. Conclusion: The seroprevalence of infection by Borrelia species responsible for Lyme disease is high in Isere; this probably reduces the predictive positive value for Lyme disease of ELISA and WB IgG, suggesting that this serological test should not be performed for nonspecific symptoms.

Examination of Diagnostic Performance of New IgG4 Rapid Test Compared with IgG- and IgG4-ELISAs to Investigate Epidemiology of Strongyloidiasis in Northeast Thailand.

Strongyloidiasis, caused by Strongyloides stercoralis, is a neglected tropical disease with a global distribution. The infection can be fatal in immunocompromised individuals, and accurate diagnosis leading to timely treatment can save lives. Serodiagnosis is a sensitive method for diagnosis and is recommended for screening high-risk individuals. A point-of-care rapid test will facilitate the screening activities, especially in low-resource settings. This study aims to apply a new IgG4 immunochromatographic test using S. stercoralis recombinant antigen (SsRapid® cassette test) and to compare it with in-house IgG and IgG4 enzyme-linked immunosorbent assays (IgG- and IgG4-ELISAs) using native Strongyloides ratti antigen to investigate the epidemiology of strongyloidiasis in northeast Thailand. A total of 300 people participated, with 136 males and 164 females of a similar mean age. The reference tests were fecal examinations using the formalin-ethyl acetate concentration technique and an agar plate culture technique. The prevalence of S. stercoralis determined by SsRapid (81.7%) was significantly higher than that by fecal examinations (43.3%) or by antibody detection by IgG-ELISA (53.0%) or IgG4-ELISA (44.0%). The diagnostic sensitivities of SsRapid, IgG-ELISA, and IgG4-ELISA were found to be 93.9%, 77.7%, and 63.1%, respectively. The rate of positive tests by the SsRapid was significantly correlated to the levels of Strongyloides-specific IgG4 and IgG antibodies. By all diagnostic methods, male participants had a significantly higher prevalence of strongyloidiasis than females. Age was significantly associated with the concentration of specific serum IgG but not with the SsRapid grading score. In conclusion, SsRapid was shown to be a sensitive and valuable diagnostic test for the epidemiology study of strongyloidiasis.

Scrub typhus in Indonesia: A cross-sectional analysis of archived fever studies samples.

Scrub typhus is an understudied vector-borne bacterial infection. We tested archived fever samples for scrub typhus seropositivity to begin charting its geographic distribution in Indonesia. We analysed 1033 serum samples from three sites. IgM and IgG enzyme-linked immunosorbent assay (ELISA) against Orientia tsutsugamushi was performed using Karp, Kato, Gilliam, TA 716 antigens. To determine the cutoff in the absence of a presumed unexposed population and gold standard tests, we identified the visual inflection point, performed change point analysis, and used finite mixture models. The optical density cutoff values used for IgM and IgG were 0.49 and 0.13, respectively. Across all sites, IgM seropositivity was 4.6% (95% CI: 3.4 to 6.0%) while IgG seropositivity was 4.4% (95% CI: 3.3 to 5.8%). The overall seropositivity across sites was 8.8% (95% CI: 8.1 to 11.7%). The overall seropositivity for Jambi, Denpasar, Tabanan were 9.7% (95% CI: 7.0 to 13.3%), 8.0% (95% CI: 5.7 to 11.0%), 9.0% (95% CI: 6.1 to 13.0%), respectively. We conclude that O. tsutsugamushi exposure in humans occurred at all sites analysed and could be the cause of illness in some cases. Though it was not the main cause of acute fever in these locations, it is still important to consider scrub typhus in cases not responding to beta-lactam antibiotics. Future seroprevalence surveys and testing for scrub typhus in acute febrile illness studies will be essential to understand its distribution and burden in Indonesia.

Comparative seropositivity of Listeria monocytogenes in the serum of pregnant women with and without a history of abortion by serological and culture methods.

Listeria monocytogenes is a major cause of miscarriage and postpartum infections in infant. Determining antibody levels against listeriolysin O can be valuable for diagnosing both invasive listeriosis and febrile gastroenteritis. However, serological methods that detect antibodies against incomplete forms of listeriolysin O can be more specific. The objective of this study was to identify (Listeria monocytogenes) in the serum of pregnant women using serological and culture methods. Clinical samples (120 cases) were collected from pregnant women with a gestational age of less than 20 weeks. Diagnosis of Listeria monocytogenes was conducted using culture methods to identify anti-Listeria antibodies. Statistical analysis of the results was conducted using IBM SPSS Statistics version 23.0 (New York, USA), Pearson's Chi Square and fisher tests. The number of positive samples by culture and ELISA was 24.16% (29) and 28.3% (34), respectively. Out of the 29 positive sample by the culture method, 10 individuals had no abortion history, 16 and 3 individuals had 1 and 2 abortions and no sample had 3 abortions. Maybe, the more abortions a person has had, the less likely they are to be infected. In the Enzyme Linked Immuno-Sorbent Assay (ELISA) method, 13 individuals tested positive for both IgG and IgM antibodies and 38 individuals tested negative. Additionally, among the positive individuals with 1, 2, and 3 miscarriages, 0, 17, and 3 people were positive for the IgG antibody and 0, 18, and 3 individuals were positive for the IgM antibody. The analysis results indicated that there was no significant relationship between culture and abortion history (p = 0.316), IgG ELISA and history of miscarriage (p = 0.672) and IgM ELISA and history of miscarriage (p = 0.552). There was no significant relationship between infection with Listeria monocytogenes and abortion (p ⩾ 0.05) in our samples. These results should be interpreted with caution due to the limitation of our small sample size.

Seroconversion and seroprevalence of TORCH infections in a pregnant women cohort study, Mombasa, Kenya, 2017-2019.

Women infected during pregnancy with TORCH (Toxoplasmosis, Other, Rubella, Cytomegalovirus, and Herpes simplex viruses) pathogens have a higher risk of adverse birth outcomes including stillbirth / miscarriage because of mother-to-child transmission. To investigate these risks in pregnant women in Kenya, we analyzed serum specimens from a pregnancy cohort study at three healthcare facilities. A sample of 481 participants was selected for TORCH pathogen antibody testing to determine seroprevalence. A random selection of 285 from the 481 participants was selected to measure seroconversion. These sera were tested using an IgG enzyme-linked immunosorbent assay against 10 TORCH pathogens. We found that the seroprevalence of all but three of the 10 TORCH pathogens at enrollment was >30%, except for Bordetella pertussis (3.8%), Treponema pallidum (11.4%), and varicella zoster virus (0.5%). Conversely, very few participants seroconverted during their pregnancy and were herpes simplex virus type 2 (n=24, 11.2%), parvovirus B19 (n=14, 6.2%), and rubella (n=12, 5.1%). For birth outcomes, 88% of the participant had live births and 12% had stillbirths or miscarriage. Cytomegalovirus positivity at enrolment had a statistically significant positive association with a live birth outcome (p=0.0394). Of the 10 TORCH pathogens tested, none had an association with adverse pregnancy outcome.

Serodiagnosis of Brucellosis in Patients with Fever of Unknown Origin at a Tertiary Care Hospital in Bangalore: A Cross-sectional Study

Introduction: Brucellosis is a zoonotic disease caused by bacteria of the genus Brucella. Although it is not commonly transmitted between humans, it can be transmitted through direct handling of cattle or their products, such as raw milk, unevenly heated milk, clotted cream, and cheese, for varying periods. Brucellosis is considered as one of the neglected zoonotic diseases worldwide, as it can cause debilitating acute infections and later become chronic with numerous complications. Aim: To determine the prevalence of brucellosis among patients with Pyrexia of Unknown Origin (PUO). Materials and Methods: This cross-sectional study was conducted in the Department of Microbiology at Ramaiah Medical College and Teaching Hospital in Bangalore, Karnataka, India, over a period of two years, from December 2019 to December 2021. The study included patients who visited the Outpatient Department (OPD) and those admitted to the hospital with fever persisting for more than 5-7 days and Fever of Unknown Origin (FUO). The total sample size was 180, and 5-10 ml of blood was collected from each patient under aseptic precautions from the median cubital vein for serological tests. The blood samples were stored at 2-8°C for the Rose Bengal Test (RBT) assay and Enzyme-Linked Immunosorbent Assay (ELISA). The demographic parameters considered included clinical history, age, gender, residency, and history of animal exposure. Data analysis was performed using the statistical software Statistical Package for the Social Sciences (SPSS) version 18.0, employing the Chi-Square test, Fisher’s-Exact test, and descriptive statistics. The significance level employed was set at p-value &lt;0.05. Results: Among 180 samples, six (i.e., 3.3%) were positive for the Brucella RBT (BRBT), while 11 (i.e., 6.1%) were positive for the (ELISA IgM), and 17 (i.e., 9.4%) were positive for the (ELISA IgG). Additionally, 22 samples (i.e., 12.22%) tested positive for either ELISA of IgG or IgM (ELISA IgG/IgM). Conclusion: The present study identified 22 patients (12.22%) with Brucella-positive cases who presented with various clinical signs and symptoms, originating from different geographical locations and regardless of gender. These findings suggest that all cases of FUO presented to a clinician should be evaluated for Brucella infection.

Seroprevalence of Human Brucellosis among Syrian Refugees in Jordan, 2022.

Brucellosis is prevalent in Mediterranean countries. The aim of this study was to determine the seroprevalence of brucellosis and associated factors among Syrian refugees in Jordan. A cross-sectional study was conducted among adult Syrian refugees who attended the Public Health Lab (PHL) in Al Mafraq governorate, during the period of May-June 2022 to obtain a health certificate, which is legally required to receive governmental authorization for employment in Jordan. Blood samples were obtained from participants and a serum specimen was tested for the presence of IgG antibodies against Brucella using enzyme-linked immunosorbent assay (ELISA) IgG kits (Vircell Microbiologists, Granada, Spain). A total of 1562 Syrian refugees were enrolled in the study. Their ages ranged between 18 and 74 years, with a median age of 30 years at presentation. The majority were males (75.9%, n = 1186) and 24.1% (n = 376) were females. The Brucella ELISA IgG results were positive for 149 persons, with an overall seroprevalence rate of 9.5% (95% confidence interval: 8.0%-11.0%). Having animal-related occupations, residing outside refugee camps, consuming unpasteurized milk, handling animals or their tissues, and slaughtering animals within 6 months of study inclusion were significantly higher among the seropositive group. In the multivariate analysis, IgG-positive persons were 13 times more likely to report being diagnosed with brucellosis (OR = 13.1, 95% CI: 6.1-28.3; p ≤ 0.001). In addition, they were more likely to reside in the city of Al Mafraq, as opposed to a refugee camp (OR = 1.9, 95% CI: 1.1-3.2; p = 0.025) and to have handled animals within 6 months of study inclusion (OR = 3.1, 95% CI: 1.1-8.9; p = 0.035). In conclusion, one-tenth of adult Syrian refugees were tested positive for Brucella ELISA IgG. Being diagnosed with brucellosis, residing in the city of Al Mafraq, as opposed to a refugee camp, and handling animals within 6 months of study inclusion were significantly associated with being positive for Brucella ELISA IgG. This study illustrates the need for improved brucellosis control measures via comprehensive vaccination of animals and enhanced laboratory detection and surveillance capacities, in addition to emphasizing the need for increased awareness sessions among Syrian refugees on the safe use and preparation of dairy products and safety practices of handling animals and their tissues.